Chance the Rapper had a good day (with a little help from a famous friend)

In the absence of any holograms, the most surprising guest star of a guest star-heavy weekend was Justin Bieber, who joined Chance the Rapper on the main stage in the middle of the afternoon. Bieber, looking rather hip-hop in a white bucket hat and black bandana, enjoyed raucous and unironic applause from the crowd for his own song Confident, but failed to steal the limelight away from Chance’s joyful, potentially career-changing, performance. When Bieber had departed, Chance jumped into the audience, slapping hands, telling people, "I love you, and you, and you ..." He looks like a superstar on the up.

Sunday was all about the love

Love and positivity continued to define the day. On the Outdoor stage, Dev Hynes aka Blood Orange clutched flowers and led a band heavy with friends, including Caroline Polachek, Adam Bainbridge and Hyne’s partner Sam Urbani, through a set of sleek, uplifting pop, including a cover/ medley that segued from his own Time Will Tell into Outkast and Lana Del Rey. The latter singer told her own crowd, “Your energy feels so amazing right now,” before asking someone to light her cigarette so she could smoke. Jhene Aiko, who has popped up on key Drake and Big Sean tracks, announced, “I’m so in love with you all, is that OK?” Sipping from a china cup between songs about aliens, bereavement and getting high, Aiko seemed ready to step away from guest turns and into her own zone, and the love was very much returned.

EDM smashed everything

At a certain point in the afternoon, a crowd began descending on the main stage. Queues for food trucks disappeared, beer gardens became peaceful and seats at benches were available, everywhere. Even the dance hangar, the most reliably busy location on the site, emptied out, as its population of semi-naked revellers headed west in search of Big Bouncy Hits. Make no mistake: Calvin Harris turned Coachella into a gigantic rave. It was, sadly, bad news for 'livetronica' band Big Gigantic, who clashed with Harris, and had extraordinary visuals that must have cost a fortune. At any other hour they'd have had an endless supply of bros putting their arms in the air among the lasers. As it stood they probably have a booking agent to shout at.

Guitar bands died ...

Even the PAs at Coachella favoured dance music over alternative, as chronically bad sound for bands persisted throughout Sunday. New indie groups with a guitar lean suffered from particularly low attendance, while electronic bands like Little Dragon thrived.

... until nostalgia revived them

Arcade Fire: 'they still look like they're on the Mayflower.' Photograph: Karl Walter/Getty Images for Coachella

The best guitar bands were from a different era. Neutral Milk Hotel showed their age by asking for no phones during their set, but still filled audience hearts with their odd, bittersweet acoustic anthems. Beck played a funk-driven greatest hits set that included material from his recent album, and ended with an extended version of Where It’s At. Then Arcade Fire took to the main stage and reminded us that they are one of the best live bands in the world. They still look like they're on the Mayflower and they've still got an accordian, but they also seem sure to survive this shift, and any others that follow.